1. Field of the Invention
The present invention relates to an opening and closing member control system, which can detect pinching of an object by an opening and closing member.
2. Description of Related Art
In a case where a power window system of a vehicle is designed to limit a pinching of a foreign object, it is conventionally known that a moving range of a window is divided into a plurality of equally divided moving regions, and that a standard medium value indicating a load applied to the window is set to each of the divided moving regions in such a manner that the power window system determines the pinching based on a comparison between the standard medium value and an actual load during a closing operation of the window (see, for example, Japanese Unexamined Patent Publication No. H11-81794 corresponding to U.S. Pat. No. 5,994,858).
In the power window system disclosed in Japanese Unexamined Patent Publication No. H-11-81794, a first half region of each of the divided moving region is assigned the corresponding standard medium value, and a second half region thereof is assigned a complement standard medium value, which is an average value of the corresponding standard medium value of each divided moving region and another standard medium value, which is assigned to an adjacent one of each divided moving region.
In this way, by setting the corresponding standard medium value to each divided moving region, threshold values for determining the pinching can be set without increasing memory capacity of a memory very much.
Generally, in order to reliably detect the pinching which a pinching detecting load is low, it is preferable to set a low threshold value. However, when the threshold value is merely lowered, there appears a disadvantage that the pinching tends to be erroneously detected.
Also, even at the time of that the pinching does not occur, the load (sliding resistance) to the window is not constant but indicates an overlapped load between a large change element and a small change element (undulation element). Also, these change elements may change in accordance with time or a peripheral environment.
In a technology disclosed in Japanese Unexamined Patent Publication No. H11-81794, the threshold value of each of the first and second halves of the divided moving region is set constant. In this way, in a case where the threshold value is constant in a predetermined region, and the change element mimics a characteristic of the pinching, the pinching may be erroneously detected around ends of the predetermined region.